Exposure to family conflict has been linked with later deficits in social functioning, and social difficulties are implicated in a variety of psychological disorders. The proposed study seeks to inform research into the causes and consequences of social vulnerability by identifying neural markers of maladaptive social processing among adolescents. We test a theoretical model linking family conflict to social behavior and psychological symptoms in a diverse sample of youth in late adolescence (ages 17-19) whose exposure to family conflict has been tracked as part of an eight-year, five-wave longitudinal study. We focus in particular to the neural correlates of reactivity to social exclusion, a construct we label social exclusion reactivity (SER). We will introduce participants to two functional neuroimaging (fMRI) tasks designed to assess neural SER (NSER): the Cyberball paradigm (Williams & Jarvis, 2006), a computer game that elicits feelings of social exclusion, and the Social Pain Task (Immordino-Yang, McColI, Damasio and Damasio, in press), in which youth are presented with vignettes showing others being socially excluded or rejected. Both neuroimaging tasks have been linked with increased activation in brain regions associated with distress and pain processing. We expect youth with past exposure to family conflict to display greater activation in these distress areas, as well as diminished ability to manage that distress by recruiting areas of the prefrontal cortex that have been shown to help down regulate social distress in previous studies. We also expect these neural correlates of SER to be associated with youths' psychological symptoms and with their everyday social behavior as measured during a 14-day daily diary study. By integrating these two neuroimaging protocols with longitudinal data on family conflict from multiple reporters and ecologically valid data on adolescents' real-life social interactions, the proposed project should offer an unprecedented depth of perspective on social functioning at a pivotal developmental stage. PUBLIC HEALTH RELEVANCE: Conflictual family environments and a lack of social integration have both been linked with increased mental and physical health risks across the lifespan. Research that identifies markers of social vulnerability in young people, at the level of nonconscious cognitive and affective processing, can inform understanding of psychological disorders related to social functioning and the development of interventions targeting youth at risk. Important, enduring relationships are often formed during the transition from adolescence to adulthood, while psychological symptoms may begin to emerge, warranting a focus on social difficulty during this stage of life.